When a catheter assembly is implanted into the vasculature of a patient, the catheter's distal portion is inserted through an incision into the vasculature until the distal tip is precisely located at the desired site, while the proximal portion remains outside the vasculature. The proximal end portion remains external of the patient for access to the catheter for infusion of fluids or withdrawal thereof, or for connections with a hemodialysis apparatus. In order to assure that stress and strain on the catheter assembly does not result in movement of the distal tip from its proper location, especially with a long-term catheter, a lengthy portion of the proximal catheter portion is subcutaneously anchored in the patient by use of a tunneler or a trocar, commonly involving a tunnel route over or near the clavicle as the tunneler pulls the catheter after attachment to an end thereof. Tunneling may be performed either by attachment of the tunneler to the distal catheter end prior to its insertion into the vasculature, or by attachment to the proximal end of the catheter for tunneling after the distal portion has been placed in the vein, termed retrograde tunneling.
Commonly, the tunneler is a generally inflexible cylindrical shaft with a blunt tip for advancing subcutaneously between a location near the catheter's venous entranced site to a tunnel exit site, creating the tunnel. The opposite or connection end of the tunneler is first attachable to the catheter end, and it is later removable from the catheter end after tunneling. There are several known manners of catheter/tunneler attachment, including those disclosed in U.S. Pat. Nos. 4,453,928; 4,832,687; 5,190,529; 5,944,732; 6,453,185; and 6,872,198; and also in U.S. Patent Publications Nos. US 2004/0176739; US 2004/0193119; and US 2005/0027282. Other connections of devices to ends of catheters are disclosed in U.S. Pat. Nos. 5,360,407 and 5,637,102 wherein a proximal end of a catheter is inserted over a barbed locking device, with assistance from an outer locking sleeve to assure the connection.
In U.S. Publication No. US 2005/0027282, an adapter is disclosed attachable to the connection end of the tunneler, wherein an open end of the adapter permits insertion of the catheter end, such as the distal end portion, whereafter a plurality of gripping sections is moved into a gripping relationship to the outside surfaces of the catheter and locked into position; after tunneling the gripping sections are unlocked releasing the catheter for withdrawal.
It is desired to provide a tunneler that is easily used with small-diameter catheters.
It is further desired to provide a tunneler that is easily used with a range of catheter lumen diameters.
It is further desired to provide a tunneler for use with different types of catheters that have either a circular lumen or a D-shaped lumen.
It is further desired to provide a tunneler for small-diameter catheters that produces a subcutaneous track that is close in diameter to the small-diameter catheters.